just stick your hand in there and do it, i did it all without taking the battery out and i have huge hands so...its a tight squeeze but it just takes a bit of patients

judging by the questions he's asking, i'd say he's better off taking the battery out so he can see what he's doing clearly, i don't think he's very expeienced, but he could try doing it with the battery in 1st by all means, personally i wouldn't bother, so few things to undo to get the battery out, so little skin on the backs of my hands